2 * Copyright © 2011,2012 Google, Inc.
4 * This is part of HarfBuzz, a text shaping library.
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 * Google Author(s): Behdad Esfahbod
27 #include "hb-ot-shape-fallback-private.hh"
30 zero_mark_advances (hb_buffer_t *buffer,
34 for (unsigned int i = start; i < end; i++)
35 if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
37 buffer->pos[i].x_advance = 0;
38 buffer->pos[i].y_advance = 0;
43 recategorize_combining_class (unsigned int modified_combining_class)
45 if (modified_combining_class >= 200)
46 return modified_combining_class;
48 /* This should be kept in sync with modified combining class mapping
49 * from hb-unicode.cc. */
50 switch (modified_combining_class)
55 case HB_MODIFIED_COMBINING_CLASS_CCC10: /* sheva */
56 case HB_MODIFIED_COMBINING_CLASS_CCC11: /* hataf segol */
57 case HB_MODIFIED_COMBINING_CLASS_CCC12: /* hataf patah */
58 case HB_MODIFIED_COMBINING_CLASS_CCC13: /* hataf qamats */
59 case HB_MODIFIED_COMBINING_CLASS_CCC14: /* hiriq */
60 case HB_MODIFIED_COMBINING_CLASS_CCC15: /* tsere */
61 case HB_MODIFIED_COMBINING_CLASS_CCC16: /* segol */
62 case HB_MODIFIED_COMBINING_CLASS_CCC17: /* patah */
63 case HB_MODIFIED_COMBINING_CLASS_CCC18: /* qamats */
64 case HB_MODIFIED_COMBINING_CLASS_CCC20: /* qubuts */
65 case HB_MODIFIED_COMBINING_CLASS_CCC22: /* meteg */
66 return HB_UNICODE_COMBINING_CLASS_BELOW;
68 case HB_MODIFIED_COMBINING_CLASS_CCC23: /* rafe */
69 return HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE;
71 case HB_MODIFIED_COMBINING_CLASS_CCC24: /* shin dot */
72 return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
74 case HB_MODIFIED_COMBINING_CLASS_CCC25: /* sin dot */
75 case HB_MODIFIED_COMBINING_CLASS_CCC19: /* holam */
76 return HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT;
78 case HB_MODIFIED_COMBINING_CLASS_CCC26: /* point varika */
79 return HB_UNICODE_COMBINING_CLASS_ABOVE;
81 case HB_MODIFIED_COMBINING_CLASS_CCC21: /* dagesh */
85 /* Arabic and Syriac */
87 case HB_MODIFIED_COMBINING_CLASS_CCC27: /* fathatan */
88 case HB_MODIFIED_COMBINING_CLASS_CCC28: /* dammatan */
89 case HB_MODIFIED_COMBINING_CLASS_CCC30: /* fatha */
90 case HB_MODIFIED_COMBINING_CLASS_CCC31: /* damma */
91 case HB_MODIFIED_COMBINING_CLASS_CCC33: /* shadda */
92 case HB_MODIFIED_COMBINING_CLASS_CCC34: /* sukun */
93 case HB_MODIFIED_COMBINING_CLASS_CCC35: /* superscript alef */
94 case HB_MODIFIED_COMBINING_CLASS_CCC36: /* superscript alaph */
95 return HB_UNICODE_COMBINING_CLASS_ABOVE;
97 case HB_MODIFIED_COMBINING_CLASS_CCC29: /* kasratan */
98 case HB_MODIFIED_COMBINING_CLASS_CCC32: /* kasra */
99 return HB_UNICODE_COMBINING_CLASS_BELOW;
104 /* Note: to be useful we also need to position U+0E3A that has ccc=9 (virama).
105 * But viramas can be both above and below based on the codepoint / script. */
107 case HB_MODIFIED_COMBINING_CLASS_CCC103: /* sara u / sara uu */
108 return HB_UNICODE_COMBINING_CLASS_BELOW;
110 case HB_MODIFIED_COMBINING_CLASS_CCC107: /* mai */
111 return HB_UNICODE_COMBINING_CLASS_ABOVE;
116 case HB_MODIFIED_COMBINING_CLASS_CCC118: /* sign u / sign uu */
117 return HB_UNICODE_COMBINING_CLASS_BELOW;
119 case HB_MODIFIED_COMBINING_CLASS_CCC122: /* mai */
120 return HB_UNICODE_COMBINING_CLASS_ABOVE;
125 case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */
126 return HB_UNICODE_COMBINING_CLASS_BELOW;
128 case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/
129 return HB_UNICODE_COMBINING_CLASS_ABOVE;
131 case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */
132 return HB_UNICODE_COMBINING_CLASS_BELOW;
136 return modified_combining_class;
140 position_mark (const hb_ot_shape_plan_t *plan,
143 hb_glyph_extents_t &base_extents,
145 unsigned int combining_class)
147 hb_glyph_extents_t mark_extents;
148 if (!font->get_glyph_extents (buffer->info[i].codepoint,
152 hb_position_t y_gap = font->y_scale / 16;
154 hb_glyph_position_t &pos = buffer->pos[i];
155 pos.x_offset = pos.y_offset = 0;
158 /* We dont position LEFT and RIGHT marks. */
161 switch (combining_class)
163 case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
164 case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
165 if (buffer->props.direction == HB_DIRECTION_LTR) {
166 pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing;
168 } else if (buffer->props.direction == HB_DIRECTION_RTL) {
169 pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
174 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
175 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
176 case HB_UNICODE_COMBINING_CLASS_BELOW:
177 case HB_UNICODE_COMBINING_CLASS_ABOVE:
179 pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing;
182 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
183 case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
184 case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
186 pos.x_offset += base_extents.x_bearing - mark_extents.x_bearing;
189 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
190 case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
191 case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
193 pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width - mark_extents.x_bearing;
198 switch (combining_class)
200 case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
201 case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
202 case HB_UNICODE_COMBINING_CLASS_BELOW:
203 case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
204 /* Add gap, fall-through. */
205 base_extents.height -= y_gap;
207 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
208 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
209 pos.y_offset += base_extents.y_bearing + base_extents.height - mark_extents.y_bearing;
210 base_extents.height += mark_extents.height;
213 case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
214 case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
215 case HB_UNICODE_COMBINING_CLASS_ABOVE:
216 case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
217 /* Add gap, fall-through. */
218 base_extents.y_bearing += y_gap;
219 base_extents.height -= y_gap;
221 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
222 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
223 pos.y_offset += base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
224 base_extents.y_bearing -= mark_extents.height;
225 base_extents.height += mark_extents.height;
231 position_around_base (const hb_ot_shape_plan_t *plan,
237 hb_glyph_extents_t base_extents;
238 if (!font->get_glyph_extents (buffer->info[base].codepoint,
241 /* If extents don't work, zero marks and go home. */
242 zero_mark_advances (buffer, base + 1, end);
245 base_extents.x_bearing += buffer->pos[base].x_offset;
246 base_extents.y_bearing += buffer->pos[base].y_offset;
248 /* XXX Handle ligature component positioning... */
249 HB_UNUSED bool is_ligature = is_a_ligature (buffer->info[base]);
251 hb_position_t x_offset = 0, y_offset = 0;
252 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
253 x_offset -= buffer->pos[base].x_advance;
254 y_offset -= buffer->pos[base].y_advance;
256 unsigned int last_combining_class = 255;
257 hb_glyph_extents_t cluster_extents;
258 for (unsigned int i = base + 1; i < end; i++)
259 if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
261 unsigned int this_combining_class = recategorize_combining_class (_hb_glyph_info_get_modified_combining_class (&buffer->info[i]));
262 if (this_combining_class != last_combining_class)
263 cluster_extents = base_extents;
265 position_mark (plan, font, buffer, base_extents, i, this_combining_class);
267 buffer->pos[i].x_advance = 0;
268 buffer->pos[i].y_advance = 0;
269 buffer->pos[i].x_offset += x_offset;
270 buffer->pos[i].y_offset += y_offset;
272 /* combine cluster extents. */
274 last_combining_class = this_combining_class;
276 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
277 x_offset -= buffer->pos[i].x_advance;
278 y_offset -= buffer->pos[i].y_advance;
280 x_offset += buffer->pos[i].x_advance;
281 y_offset += buffer->pos[i].y_advance;
289 position_cluster (const hb_ot_shape_plan_t *plan,
298 /* Find the base glyph */
299 for (unsigned int i = start; i < end; i++)
300 if (is_a_ligature (buffer->info[i]) ||
301 !(FLAG (_hb_glyph_info_get_general_category (&buffer->info[i])) &
302 (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) |
303 FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) |
304 FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK))))
306 position_around_base (plan, font, buffer, i, end);
312 _hb_ot_shape_fallback_position (const hb_ot_shape_plan_t *plan,
316 unsigned int start = 0;
317 unsigned int last_cluster = buffer->info[0].cluster;
318 unsigned int count = buffer->len;
319 for (unsigned int i = 1; i < count; i++)
320 if (buffer->info[i].cluster != last_cluster) {
321 position_cluster (plan, font, buffer, start, i);
323 last_cluster = buffer->info[i].cluster;
325 position_cluster (plan, font, buffer, start, count);